Distributors of power face time-varying supply from solar and wind energy and time-varying demand for electricity from customers. The demand for electricity for the residential market, for example, is increasing due in part to the proliferation of a variety of home devices, enabling communications, Internet connectivity, multimedia and entertainment activities, or the like, in addition to more traditional home devices, such as air conditioners, water heaters, ovens, etc. Appliances in the home for each household put significant pressure on the electricity grid of local, regional or national electricity providers.
A significant issue for an electricity power provider is providing power during peak times of electricity demand. These peaks may be relatively short in terms of duration, but the electricity grid through which the electricity power provider delivers the electricity is dimensioned to support these peaks. Outside peak periods, the demand for electricity is lower, but the infrastructure to support peaks of electricity demand is still present. The electricity power providers typically try to forecast the level of demand that is likely to occur, particularly the time, duration and level of peak demands.
Peaks of electricity demand may or may not occur at the same time period within a day. Electricity power providers typically lower their price outside of the peak demand period and increase their price for power during the peak demand period, thus simply reacting to supply and demand variations. These practices may be inconvenient for the customer because the end user may have to adapt their electricity consumption patterns in response to the price, in order to control their electricity bills. However, the electricity power provider establishes some control over the forecasted demand by use of these price incentives.
Another significant issue for an electricity power provider is the management of a variety of power generation sources during peak and off-peak. The electricity power provider typically has several power generation sources, each of which may have a different power generation capacity (typically measured in kilowatts or megawatts) and sometimes using a variety of different types of power generation fuels (e.g., coal, natural gas, wind, solar, etc.). At any given time, the electricity power provider will have activated (i.e., turned on or brought online) only a minimum number of the power generation sources needed to satisfy the current electricity demand level, so that most of the power generation sources can be operated at or near their maximum power generation capacity. Then, when electricity demand increases or decreases, the electricity power provider typically activates or deactivates, respectively, another power generation source as needed. Under this technique, since most power generation sources operate most efficiently at or near their maximum power generation capacity, the electricity power provider may be able to operate all but one of the activated power generation sources at maximum power generation capacity, so that the efficiency of these power generation sources is maximized. The one other activated power generation source, on the other hand, does not necessarily operate at maximum capacity or efficiency, since it simply produces electricity at whatever level is needed to fill out the current electricity demand. In this manner, the electricity power provider achieves the highest operating efficiency (and lowest cost) for its overall power generation operations, except for the power generation source that is not operating at maximum capacity.